组合了电源控制、用户输入功能的单刀单掷按钮开关

本设计实例介绍了对某种旧设计的增强措施(参考资料1)。图1中的电路使用常开型单刀单掷按钮开关S1,它代替了原始设计要求的单刀双掷开关。您可以使用膜片开关来大大简化该器件的工业设计并增强它的人机控制特性。另外,该电路消除了流过未动作开关的电流,由此略微减少了工作模式中的泄漏电流。     

Unfreezable Water in Apple Treated by Pulsed Electric Fields: Impact of Osmotic Impregnation in Glycerol Solutions

The effects of pulsed electric fields (PEF) and osmotic impregnation in glycerol solution on the amount of unfreezable water in apple were determined by means of low-temperature differential scanning calorimetry (DSC). The obtained data were compared with behaviour of pure water–glycerol solutions (sample WG). PEF treatment was applied using a near-rectangular monopolar generator with pulse duration of 100 μs at electric field strength of 800 V/cm. The osmotic impregnation of PEF-treated apple discs was done using water–glycerol (sample AWG) and apple juice–glycerol (sample AJG) osmotic solutions at different concentration of water or juice in glycerol, W = 30–100 wt%. The data evidenced that for the PEF-treated samples the glycerol was able to penetrate successfully inside apple tissue. The state diagrams for WG, AWG and AJG samples were rather similar. It was observed that free water existed only for moisture content above some minimum value. The unfreezable water content was the largest in AJG, followed by WG and AWG. The juice concentration in glycerol W ≈ 80 wt% was found to be optimal for preservation of the texture of PEF-treated samples.     

Novel acylflavones from Sideritis syriaca ssp. syriaca

In the framework of the detailed phytochemical analysis of the aerial parts of Sideritis syriaca, two novel acylflavones were isolated together with three acetylated flavone glycosides and acylated flavone glycosides. The novel acylflavones were identified as isoscutellarein 7-trans-p-coumarate and apigenin 7-,4′-bis(trans-p-coumarate). Their structures were elucidated by means of UV, 1D and 2D NMR, LC–DAD–MS and confirmed by HR-MS spectroscopy.     

Group stress, authoritarian style of control, and use of power.

Studied the influence of group stress on proclivities toward an authoritarian style of leadership and on use of power by industrial foremen and supervisors in their relations with members of a supposed work crew. 25 supervisors were assigned to a group-stress condition and 25 to a neutral condition. Group stress was simulated by having a member of the work crew disparage both the experimental task and the supervisor. By so behaving, the problem worker had a negative impact on group morale. A set of rating categories was constructed for assessing authoritarian style of leadership, and these ratings were converted to a quantitative index. Supervisors subjected to group stress revealed a significantly greater tendency toward authoritarian modes of control and gave lower pay increases ( p     

A study of the usefulness of Lanyon's Psychological Screening Inventory with adolescents.

Administered the Psychological Screening Inventory (PSI) to 559 male and 564 female 13-16 yr olds. Normative test data are presented. On the basis of a questionnaire administered with the PSI, this group was divided into 2 groups on the basis of whether they were more or less likely to appear in court, and were compared to a group tested while on juvenile probation. Significant differences were found on several PSI scales. It appears that the PSI can serve a useful purpose when administered to 13-16 yr olds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in the inhibition of recall as a function of retrieval cues.

Asked 64 Ss from 3 age ranges (18–37, 50–64, and 65–88 yrs) to look at word lists in which the words were either categorized under headings or additionally subcategorized. Ss were then asked to recall the words when (a) the category name was given, or (b) the category name and half of the list words were given. Words recalled decreased with increasing age in all conditions. The youngest age group recalled more words when the category name only was used as a recall cue. There were no significant differences between the 2 recall conditions for the other age groups, suggesting that they were not as susceptible to recall inhibition as the younger adults. (5 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading group membership in first grade: Teacher behaviors and pupil experience over time.

Examined the implementation of reading groups in 3 1st grade classrooms (N = 60) and its effects over the 1st 5 mo of the school year on pupil mobility, on patterns of teacher-child contact as measured by J. E. Brophy and T. L. Good's (1970) dyadic interaction system, and on pupil measures of reading achievement and related factors. Results indicate that relatively fixed membership in reading groups did not emerge until the end of the 1st month of school. Group membership was found to contribute a significant increment of 25% to the prediction of pupil reading achievement at midyear over and above initial readiness differences among the students. Differential teacher feedback favoring members of the highest reading group was not documented. Additional qualitative evidence suggested a reconceptualization concerning the mediation of the expectancy effect. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cr(VI) removal from aqueous solution by activated carbon coated with quaternized poly(4-vinylpyridine)

A composite sorbent (GAC-QPVP) was prepared by coating poly(4-vinylpyridine) onto a granular activated carbon, followed by cross-linking and quaternization processes. The sorbent was characterized by scanning electron microscopy, point of zero charge measurement, and BET analysis. Batch experiments with variable pH, ionic strength, and concentrations of Cr(VI), sorbent, and competing anions were conducted to evaluate the selective sorption of Cr(VI) from aqueous solutions. The results showed that Cr(VI) sorption rates could be described by a reversible second-order kinetics, and equilibrium uptake of Cr(VI) increased with decreasing pH, decreasing ionic strength, and increasing sorbent concentration. The estimated maximum equilibrium uptake of chromium was 53.7 mg/g at pH = 2.25, 30.7 mg/g at pH = 3.65, and 18.9 mg/g at pH = 6.03, much higher than the maximum capacity of PVP-coated silica gel, an adsorbent for Cr examined previously. When compared with the untreated granular activated carbon, sorption onto GAC-QPVP resulted in much less Cr(VI) reduction and subsequent release of Cr(III). The effect of phosphate, sulfate, and nitrate was minor on the selective sorption of Cr(VI). An ion exchange model that was linked with aqueous speciation chemistry described Cr(VI) sorption reasonably well as a function of pH, ionic strength, and Cr(VI) concentration. Model simulations suggested that sorbed Cr(VI) was partially reduced to Cr(III) on the sorbent when pH was less than 4. The presence of Cr(III) on the sorbent was confirmed by the X-ray photoelectron spectroscopic analysis. Overall, the study has demonstrated that GAC-QPVP can effectively remove Cr(VI) from aqueous solutions under a wide range of experimental conditions, without significant Cr(III) release associated with the virgin GAC treatment.     

Emissions of metals associated with motor vehicle roadways

Emissions of metals and other particle-phase species from on-road motor vehicles were measured in two tunnels in Milwaukee, WI during the summer of 2000 and winter of 2001. Emission factors were calculated from measurements of fine (PM2.5) and coarse (PM10) particulate matter at tunnel entrances and exits, and effects of fleet composition and season were investigated. Cascade impactors (MOUDI) were used to obtain size-resolved metal emission rates. Metals were quantified with inductively-coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence (XRF). PM10 emission rates ranged from 38.7 to 201 mg km(-1) and were composed mainly of organic carbon (OC, 30%), inorganic ions (sulfate, chloride, nitrate, ammonium, 20%), metals (19%), and elemental carbon (EC, 9.3%). PM10 metal emissions were dominated by crustal elements Si, Fe, Ca, Na, Mg, Al, and K, and elements associated with tailpipe emissions and brake and tire wear, including Cu, Zn, Sb, Ba, Pb, and S. Metals emitted in PM2.5 were lower (11.6% of mass). Resuspension of roadway dust was dependent on weather and road surface conditions, and increased emissions were related to higher traffic volumes and fractions of heavy trucks. Emission of noble metals from catalytic converters appeared to be impacted by the presence of older vehicles. Elements related to brake wear were impacted by enriched road dust resuspension, but correlations between these elements in PM2.5 indicate that direct brake wear emissions are also important. A submicrometer particle mode was observed in the emissions of Pb, Ca, Fe, and Cu.